Please explain how to do these!

Write the Lewis structure and chemical formula of the compound with a molar mass of about 70 g/mol that

contains 19.7% nitrogen and 80.3% fluorine by mass, and determine the formal charge of the atoms in this

compound.

Evaporation of sweat requires energy and thus take excess heat away from the body. Some of the water that you

drink may eventually be converted into sweat and evaporate. If you drink a 20-ounce bottle of water that had been in

the refrigerator at 3.8 °C, how much heat is needed to convert all of that water into sweat and then to vapor?? (Note:

Your body temperature is 36.6 °C. For the purpose of solving this problem, assume that the thermal properties of

sweat are the same as for water.)